Medication adherence and predictive factors in patients with cardiovascular disease: A comparison study between Australia and Iraq

Background: Adherence to cardiac medication regimes is essential for effective treatment of cardiovascular disease but is unsatisfactory in Australia and little studied in Iraq. Aim: This study evaluated and compared adherence to cardiac medications and potentially predictive factors based on the Theory of Planned Behaviour (TPB) in patients with cardiovascular disease admitted to hospital and attending cardiac services in Australia and Iraq. Methods: A cross-sectional multi-centre comparative study involving 246 cardiac patients was conducted in Australia (one hospital in Sydney) and Iraq (three cardiac hospitals in Baghdad) between October 2016 and December 2017. Adherence to medications and related factors were examined using established, validated questionnaires, formally translated and validated into Arabic for Iraqi participants. Binary logistic regression was conducted to determine those factors independently predictive of cardiac medication adherence, in Australia and Iraq. Findings: A significantly higher proportion (64.3%) of Iraqi than Australian (37.5%) cardiac patients reported medium/low levels of adherence to their cardiac medications. After adjusting for confounding factors, the ability to correctly self-administer and refill medications, and beliefs about cardio-protective medication were identified as independent predictors of cardiac medication adherence behaviour in both Australian and Iraqi participants. In Iraq, patients recruited from out-patient cardiac clinics were significantly more likely to report adherent behaviours that patients recruited as in-patients of the cardiac ward. Conclusion: Non-adherence to cardiac medications differed but was sub-optimal in both Australian and Iraqi patient samples, in both countries, adherence was associated with patients’ beliefs about medications, and ability to self-administer and refill medications. Clinical nurses and pharmacists need to investigate these factors at every point in the cardiac trajectory to optimise medication adherence.